BOSTON -- The defense of the Boston Bruins dominated the Eastern Conference Final so thoroughly that it made absolutely perfect sense for a stay-at-home defenseman to score the only goal in Game 4 on Friday.

Adam McQuaid, who had one previous postseason goal and seven career goals in the regular season, rifled a slap shot just under the crossbar early in the third period to provide the winning margin in a 1-0 victory at TD Garden that allowed Boston to complete a stunning sweep of the top-seeded Pittsburgh Penguins.

With the win, Boston advances to the Stanley Cup Final for the second time in three seasons, where it will face either the Chicago Blackhawks or the Los Angeles Kings. The Blackhawks lead the best-of-7 Western Conference Final 3-1 and get their first chance to clinch Saturday with Game 5 at United Center (8 p.m. ET; NBC, CBC, RDS).

"It obviously feels good," McQuaid said of his goal. "It feels good to be able to contribute that way when you don't normally.

"But I think you look at so many great efforts we had from guys tonight. The last 10 minutes of the game, guys were all over the ice, doing whatever it took to preserve that goal. You know, [goalie] Tuukka [Rask] was phenomenal again for us."

In essence, that was Boston's game plan for the series. Play a five-man team defense in the hope of smothering Pittsburgh's big guns. Allow Rask to do what he does best, and score some opportune goals.

But even the Bruins didn't know that blueprint had the ability to build something so beautiful.

Pittsburgh managed two goals in the series, and neither came from its biggest stars -- Sidney Crosby, Evgeni Malkin, Kris Letang, James Neal or NHL Trade Deadline import Jarome Iginla. Pittsburgh managed one goal in the final 106 minutes and 28 seconds of the series and was outscored 12-2 in the four games. Most tellingly, Pittsburgh never led in the series and was tied for 75:02 of the 275:19 of game play.

"If you look back, the chances are there," said Crosby, who had no points, 13 shots and was minus-2 in the series. "You try to fight, you try to get through to the net and get rebounds, and sometimes they come to you -- sometimes they don’t.

"But obviously, you score two goals as a team in four games and virtually we go without any points. That doesn’t sit very well."

Letang, the top-scoring defenseman in the playoffs heading into this round, had no points, 16 shots and was a minus-5.

"They play really well defensively and we didn’t manage to score goals," he said. "The goalie played really well, and some of the bounces didn’t go our way. But they’re a good team, and they move on and we’re not. So that’s the end of the story."

Actually, Pittsburgh's offensive struggles are the beginning of the story for this Boston team, which has lost once in its past 10 games after surviving a first-round Game 7 against the Toronto Maple Leafs. During the course of this series, the Bruins illustrated how lethal a combination their suffocating defense and Rask playing at the top of his game can be.

The Penguins entered the third round as the highest-scoring team in the 16-team tournament. They went home for a long summer of soul-searching wondering what happened to an offense that was averaging 4.27 goals through two rounds. They are the first team since 2009 to trail for an entire series -- a dubious distinction last achieved by the Columbus Blue Jackets against the heavily favored Detroit Red Wings in the first round of the 2009 Stanley Cup Playoffs.

"It just shows what a team can do," said defenseman Dennis Seidenberg, who joined Zdeno Chara as Boston's top shutdown pair. "They have a lot of firepower, a lot of quality scorers over there. But if you play as a team, defend as one, I think you can do what we did in this series, and that was just playing good defense, a lot of layers and play hard."

It also didn't hurt that the Bruins had Rask as their line of last defense. The goalie, who was a backup when Boston won the Cup in 2011 with Tim Thomas delivering clutch performance after clutch performance, stopped 134 of the 136 shots he faced. That, by the way, is a save percentage of .985.

In the dying seconds of Game 4, Rask made a couple of saves, including a glove save on Iginla at the buzzer, to preserve his second shutout of the series as the Penguins threw everything they had into trying to tie the score and extend their season. As he had done throughout the series, Rask left the game's best offensive players shaking their heads.

"Well, [Rask] saved us again, I mean especially at the end it seemed like there were 10 guys out there for our shift," Seidenberg said. "They were throwing pucks everywhere and he seemed to just find the lane and find the puck and get his glove or a body part on it. I mean [Chara] I think, at the end I thought the puck was in, and [Chara] stretches his arm and somehow it hits his arm. We did have a little bit of luck, but again we played a good team defense, and having Tuukka back there definitely helps."

The Bruins go into the Final with their game seemingly in top gear again and four wins from adding to the championship they won in a seven-game title series against the Vancouver Canucks 24 months ago.

"It’s awesome," forward Milan Lucic said. "Being through what we’ve been through as a team over the years, and even this year with everything that happened in the first round and Game 7 [against Toronto] and just going through that and getting to this point, it’s truly a great feeling.

"I think we definitely need to enjoy this tonight. We don’t know who we’re playing yet, so like I said, just enjoy it the next couple of days and then regroup, refocus, and go out there and start having fun again."